.github: extract new sof-docs.yml from pull-request.yml

More progress towards trimming down pull-request.yml

Important benefit and "secret" agenda: remove the constantly failing
sof-docs from daily builds, which will make them green again.

Green daily builds are important to quickly spot regressions like for
instance #9797

Signed-off-by: Marc Herbert <marc.herbert@intel.com>

Author: marc-hb

.github/workflows/pull-request.yml

@@ -63,44 +63,6 @@ jobs:
           ninja -C docbuild -v doc
 
 
-  # This is unfortunately a mix of sof-docs/.github/ + the previous job
-  # above, duplicating a bit of both: please keep in sync with both. We
-  # build sof-docs here too because waiting for sof-docs CI to find
-  # regressions introduced in sof.git is very time-consuming, see
-  # example in
-  # https://github.com/thesofproject/sof/pull/5731#issuecomment-1175630147
-  sof-docs:
-    runs-on: ubuntu-20.04  # sof-docs is still stuck to this for now
-
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          filter: 'tree:0'
-
-      - name: apt-get update
-        run: sudo apt-get update
-
-      - name: apt-get install
-        run: sudo apt-get -y install
-             doxygen make default-jre graphviz cmake ninja-build
-
-      - name: doxygen
-        run: cmake -GNinja -S doc/ -B doxybuild/ && ninja -C doxybuild/ -v doc
-
-        # Nested git clone, this is fine
-      - name: clone sof-docs
-        run: git clone https://github.com/thesofproject/sof-docs sof-docs/
-
-      - name: PATH += .local/bin
-        run: echo "$HOME/.local/bin" >> $GITHUB_PATH
-
-      - name: 'pip install -r sof-docs/scripts/requirements.txt'
-        run: pip install -r sof-docs/scripts/requirements.txt
-
-      - name: build sof-docs
-        run: make -C sof-docs/ html SOF_DOC_BUILD="$(pwd)"/doxybuild/
-
-
   # This is a bit redundant with the other jobs below and with the (much
   # faster!) installer[.yml] but it may differ in which platforms are
   # built.  This makes sure platforms without any open-source toolchain

.github/workflows/sof-docs.yml

@@ -0,0 +1,57 @@
+---
+# yamllint disable-line rule:truthy
+on:
+  push:
+    branches:
+      - 'main'
+      - 'stable-**'
+      - '**-stable'
+  pull_request:
+    branches:
+      - 'main'
+      - 'stable-**'
+      - '**-stable'
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+  # Allows to call this forkflow from other workflows
+  workflow_call:
+
+jobs:
+
+  # This is unfortunately a mix of sof-docs/.github/ + pull-request.yml#doxygen
+  # duplicating a bit of both: please keep in sync with both. We
+  # build sof-docs here too because waiting for sof-docs CI to find
+  # regressions introduced in sof.git is very time-consuming, see
+  # example in
+  # https://github.com/thesofproject/sof/pull/5731#issuecomment-1175630147
+  sof-docs:
+    runs-on: ubuntu-20.04  # sof-docs is still stuck to this for now
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          filter: 'tree:0'
+
+      - name: apt-get update
+        run: sudo apt-get update
+
+      - name: apt-get install
+        run: sudo apt-get -y install
+             doxygen make default-jre graphviz cmake ninja-build
+
+      - name: doxygen
+        run: cmake -GNinja -S doc/ -B doxybuild/ && ninja -C doxybuild/ -v doc
+
+        # Nested git clone, this is fine
+      - name: clone sof-docs
+        run: git clone https://github.com/thesofproject/sof-docs sof-docs/
+
+      - name: PATH += .local/bin
+        run: echo "$HOME/.local/bin" >> $GITHUB_PATH
+
+      - name: 'pip install -r sof-docs/scripts/requirements.txt'
+        run: pip install -r sof-docs/scripts/requirements.txt
+
+      - name: build sof-docs
+        run: make -C sof-docs/ html SOF_DOC_BUILD="$(pwd)"/doxybuild/